As the era of an extraordinarily advanced age is coming in this country, there is a drastically growing increase year by year in the number of the aged who cannot turn their bodies over or a round in bed by themselves. This undoubtedly increases the number of the aged who suffer from wounds of the skin caused by a stayed in bed without turning over or around. Further, there is the increase in numbers of traumatogenic wounds of the skin caused, for example, by traffic accidents. From such background, growing attention has recently been drawn in various fields to the significance of treating skin diseases. In particular, the skin of the aged is in a state considerably different from that of the young in terms of its structure and functions, and there are many different kinds of skin diseases peculiar to the aged. Unfortunately however, currently drugs highly effective for curing or healing such skin diseases has been developed.
Skin diseases occurring in many cases of the aged who cannot turn over or a round in bed by themselves, include intractable skin ulcers such as, for example, decubitus ulcers, burns caused at low temperature, and so on. Further, the aged poor in a systemic state are likely to have their whole bodies infected with opportunistic viruses including herpes viruses such as, for example, simplex virus, cytomegalo virus, or the like. This systemic infection with such viruses may in many cases accompany various symptoms on the skin, like zoster.
On the other hand, currently, as there are no topical preparations suitable for the treatment of skin diseases with a portion of the skin tissues depressed or for the treatment of skin ulcers caused by circulatory disorders such as buerger, diabetes, phlebothrombosis, and so on, such treatment may suffer from difficulty in many cases.
It can be said that a topical preparation capable of applying a medicament directly to the site of lesion is one of the most superior drug delivery systems for administering such a medicament; however, research and studies on such a drug delivery system for administering topical preparations are less advanced. As things stand today, for instance, it can be said that few medicaments have been developed originally for topical application. As topical preparations, there have been extensively employed adrenocortical hormones as if they are an all-round drug therefor. In fact, the adrenocortical hormones are highly effective for many skin diseases; however, careful attention should be paid to the fact that there are many cases in which the application of the adrenocortical hormones worsens a lesion or symptom of some skin disease, e.g. skin ulcers such as decubitus ulcers, burns, etc., zoster and traumatogenic wounds caused by the abrasion of the skin and by the defect of the skin, and so on. Hence, the adrenocortical hormones should not be randomly applied.
In treating the ulcerated skin diseases such as decubitus ulcers, burns at low temperature and crus ulcers as well as the traumatogenic wounds of the skin, the site of a lesion is sterilized and topical preparations containing a chemical agent are applied for the purpose of a prevention of infection. This therapy is dependent mainly upon the natural curing ability of the living body for curing the lesion and symptom of the skin disease. However, as things stand today, few medicaments can positively and actively cure and heal the lesions and symptoms of the skin diseases. In this country, "Bendazac", or [(1-benzyl-1-H-indazol-3-yl)oxy]acetic acid, is the only one that can be adapted to the treatment of ulcers of the skin. Further, bovine blood extract preparations are employed as agents for accelerating the formation of granulation tissues. These medicaments, however, cannot always offer satisfactorily curing effects.
A major therapy for the treatment of the zoster uses topical preparations containing a non-steroid type anti-inflammatory and analgesic agent, while preventing infection with a pathogen by application of an antibiotic ointment. This therapy is conducted mainly in order to mitigate clinical symptoms of the zoster.
It should be noted herein that the term "skin ulcer" or related terms are intended to mean wounds of the skin, caused by the defect of the skin tissues, such wounds having depression to some depth inside the body due to the necrosis of the skin tissues. The term `skin ulcer` is employed as different from the term "erosion" that is intended to mean wounds of the skin which do not reach the dermis of the skin. The ulcers of the skin may be attributed to various causes. Intractable skin ulcers may include, for example, (1) a decubitus ulcer and a crus ulcer, caused by disorders of local circulation; and (2) skin ulcers caused by burns, frostbite or congelation, disorders by radiation, and so on.
In addition, the zoster caused by infection with cytomegalo virus is such that bullas or blisters occurring in crowds in an initial stage turn gradually into erosion and an ulcer and they are usually cured or healed without particular treatment or naturally in several weeks. In many cases, an ache lasts during this period and such an ache may become less as the exanthema on the skin disappears. However, in order to alleviate pain of a patient, it is of significance to treat and cure the exanthema on the skin.
Furthermore, if a portion of the skin tissues has been lost by an injury or burns or for other reasons, it is needless to say that the skin tissues be repaired immediately to avoid infection. What is common in these disease conditions is the necessity of promoting the propagation of granulation tissues and the sloughing in order to rapidly repair or reflect the skin tissues at the site of the lesion where they are lost due to erosion of the skin, an ulcer or by a physical impact.
In order to improve such defects and disadvantages of conventional medicaments, research has been made for developing new topical preparations for healing wounds of the skin. As a result, there have been made reports on topical preparations containing as a pharmaceutically effective compound (teprenone) (as disclosed in Japanese Patent Examined Publication No. 64-10,495) and (plaunotol) (as disclosed in Japanese Patent Examined Publication No. 2-33,008). However, these topical preparations have not yet entered into the market.